condition mean min max ZT0-3 6.262628333333334 2.6077500000000002 8.275105 ZT4-7 3.139065 3.139065 3.139065 ZT8-11 4.809235 4.809235 4.809235 ZT12-15 10.567235 9.883230000000001 11.25124 ZT16-19 13.53495 13.53495 13.53495 ZT20-23 14.711549999999999 14.711549999999999 14.711549999999999